Retro-reflex sensor with teach-free technology

Discover the teach-free retro-reflex sensors from wenglor. Automatic object detection without teach-in, reliable for transparent, shiny and reflective materials – ideal for packaging, logistics and the beverage industry.

Die P1KK-Sensoren sind besonders vorteilhaft beim Transport von kleinen und großen Objekten auf Förderbändern mit unterschiedlichem Abstand zwischen Sender und Reflektor.

What is a retro-reflex sensor?

Basic principle of retro-reflex

A retro-reflex sensor combines an emitter and receiver in one housing. The light is emitted, hits a reflector and returns to the receiver. If the light beam is interrupted or attenuated by an object, the sensor recognizes this as a switching signal.

With classic retro-reflex sensors, a teach-in is necessary: the sensor is calibrated to the object situation to be detected (e.g. brightness, position).

Teach-free technology: automatic adjustment

With Teach-Free, this manual teach-in step is no longer necessary. The sensor adjusts itself automatically:

  • The switching point (threshold value) is automatically adjusted dynamically – even in the event of contamination, ageing or temperature fluctuations.
  • The sensor uses its internal Logic and ongoing signal changes to reliably detect without the user having to readjust.

This makes the application easier and more robust in everyday use.

Ready for immediate use without readjustment – in the video, Michael and Mike explain the benefits of teach-free technology for SLR sensors. They demonstrate how to achieve reliable object detection without manual teach-in – especially with low-reflection or transparent objects.

Step-by-step: How to use a retro-reflex sensor with teach-free technology

Here is a typical procedure for initial start-up and use:

  1. Positioning: Position the sensor so that it is directed towards the reflector – if possible without disturbing light reflections or shadows.
  2. Reflector mounting: Use the appropriate reflector (e.g. RQ or RE types from wenglor). The sensor “sees” via this reflector.
  3. Switching on & automatic calibration: When the sensor is powered up, the teach-free adjustment starts automatically: the sensor analyzes light conditions and sets the switching point internally.
  4. Insert test object: A transparent or low-reflection object passes through the light beam. The sensor uses the signal change to assess whether a switching event has occurred.
  5. Fine adjustment (optional, via IO-Link): If necessary, parameters such as sensitivity, hysteresis or delays can be adjusted via IO-Link.
  6. Continuous operation with adaptation: During operation, the sensor adapts its switching thresholds to changing conditions (e.g. ageing, slight contamination) without manual intervention.

Reliable object detection and application options

Advantages over classic teach-in sensors

  • No manual calibration required → simpler installation
  • Automatic adaptation to environmental changes
  • Robust against contamination or ageing
  • Less risk of failure due to incorrectly set switching thresholds

Example applications

The teach-free sensors from wenglor are particularly suitable for difficult materials and changing products:

  • Packaging industry: detection of films, PET bottles and transparent packaging
  • Beverage industry: Reliable detection of bottles, cans and reusable containers
  • Logistics & conveyor technology: Precise recording of parcels, cartons and objects
  • Plastic and film processing: monitoring transparent components and film webs

Conclusion

With its teach-free technology, wenglor is setting new standards in photoelectronic sensors. The automatic adjustment of the switching point completely eliminates the need for manual teach-in – with maximum reliability and precision. Whether in the packaging industry, logistics or beverage production: Teach-Free retro-reflex sensors from wenglor guarantee reliable object detection, reduced maintenance and maximum process stability – without any manual adjustment.